摘要
本研究采用以O2为氧化剂、CuO为催化剂的催化湿法氧化技术去除拜尔液中的有机物.首先,在O2添加量为13.98 g/L、氧化温度为220℃、氧化时间为100 min、不添加CuO的条件下,总有机碳、腐植酸钠和草酸钠的去除率分别为86.59%、92.96%和71.36%.在此基础上,研究了O2氧化拜尔液中有机物的自由基链式反应机理.然后,在CuO添加量为6%、O2 添加量为13.98 g/L、催化温度为250℃、催化时间为100 min的最佳条件下,总有机碳去除率为98.36%,腐植酸钠和草酸钠基本能够被全部去除.CuO形成的铜羟基络合物([Cu(Ⅱ)(OH)x]2-x)基于络合反应机理是催化有机物降解的主要原因,溶解的CuO直接催化的自由基链式反应是第二个原因.催化湿法氧化技术能够有效去除拜尔液中的有机物,尤其是对氧化铝生产危害较大的草酸钠.
Abstract
In this study,catalytic wet oxidation technology was used to remove organic substances from Bayer liquid.First,under the optimal conditions without a catalyst(13.98 g/L of O2 addition,oxidation temperature of 220℃,and oxidation time of 100 min),the removal efficiencies of total organic carbon,sodium humate,and sodium oxalate were 86.59%,92.96%,and 71.36%,respectively.The mechanism of a free radical chain reaction of wet oxidation removal of organic substances was studied.Then,under the optimal conditions using CuO as a catalyst(13.98 g/L of O2 addition,the catalytic temperature of 250℃,the catalytic time of 100 min,and the catalyst dose of 6%of the ore added mass),the total organic carbon removal efficiency was 98.36%,and sodium humate and sodium oxalate can basically be removed completely.The catalysis of CuO was mainly reflected in two aspects:the copper hydroxyl complex([Cu(Ⅱ)(OH)x]2-x)formed by the dissolution of CuO was catalyzed based on the complex reaction mechanism,and the dissolved CuO catalyzed the free radical chain reaction.The catalytic wet oxidation technology exhibited high organic substance removal efficiency,especially for removing sodium oxalate,which could negatively affect the alumina products.
基金项目
国家自然科学基金(22068021)
国家自然科学基金(52064030)
Yunnan Young and Middleaged Academic and Technical Leaders Reserve Talent Program,China(202305AC160064)
Yunnan Major Scientific and Technological Program,China(202202AG050011)
Yunnan Major Scientific and Technological Program,China(202202AG050007)
NETL
NSTL
万方数据